In this particular topic (where a person is in life), having a goal of being married and incorporated with a timeline of “by x age”, has caused a lot of unhappy and failed marriages.
Or a goal of having children then layered with “by x age” has caused a lot of people to procreate with people they probably shouldn’t have procreated with and often at a time they weren’t really ready to procreate.
Weaving a particular timeline in some of these goals is really a bad idea.
If we’re talking about other things like buying a house, traveling to a certain place, going skydiving, etc. Then yeah, setting a timeline is probably imperative to achieving those goals.